1. Technical Field
The present invention relates to an alcohol separator which separates a higher concentration of alcohol from an alcohol solution of sake (Japanese rice wine), other alcoholic beverage raw material, or solution of volatile organic compounds.
2. Description of Related Art
The inventor has developed a separator which separates a target material with the characteristics of surface excess such as an alcohol by producing mist by means of ultrasonic waves (see Patent Document 1).
Patent Document 1: Japanese Patent Laid-Open Publication TOKUKAI No. 2001-314724 With this type of alcohol separator, an alcohol solution is filled into an ultrasonic atomization chamber with a seal structure, and the alcohol solution in the ultrasonic atomization chamber is atomized into mist by means of ultrasonic oscillation of an ultrasonic oscillator. The alcohol separator aggregates and collects the atomized mist, and separates a higher concentration of alcohol solution. More specially, the alcohol separator separates a higher concentration of alcohol solution as a target material as follows.
With an alcohol, which quickly moves to the surface and exhibits the characteristics of surface excess, the concentration of alcohol is high at its surface. When the solution is oscillated by ultrasonic oscillation, fine liquid droplets are ejected from the surface of the solution as mist into carrier gas by ultrasonic energy. The mist ejected into the carrier gas has a high concentration of alcohol. The reason is that the solution at its surface with a high concentration of alcohol is ejected as the mist. Accordingly, a solution with a high concentration of alcohol can be separated by aggregating and collecting the mist. With this method, a high concentrated alcohol solution can be separated without heating a solution. Thus, a high-concentrated target material can be separated with less energy consumption. Furthermore, since heating is not necessary, the separator has an advantage in that the target material can be separated without deterioration.
FIG. 1 is a block diagram showing an apparatus, which oscillates a solution to produce mist and then aggregates and collects the mist in a collection portion. With the ultrasonic separating apparatus of this figure, the mist produced in an ultrasonic atomization chamber 4 is aggregated and collected in a collection portion 5. The mist produced by means of ultrasonic waves is composed of fine liquid droplets ejected from a solution with a high concentration of alcohol. Since the mist as fine liquid droplets is in a liquid state, the mist can be collected by highly aggregating it. Accordingly, the mist can be aggregated by means of the electrostatic attraction forces, or by means of a baffle, which the mist collides with. With the apparatus, which aggregates and collects mist, however, the alcohol included in the mist vapors vaporizes during the process of mist collection, thus, the concentration of alcohol in the mist is gradually reduced. For this reason, the mist produced in the ultrasonic atomization chamber has a high concentration of alcohol immediately after it is produced in the ultrasonic atomization chamber, after that, the concentration of alcohol in the mist is reduced as the mist is transported to the collection portion. Both alcohol and water vaporize from the mist on the path from the ultrasonic atomization chamber to the collection portion. Alcohol tends to easily vaporize compared with water, thus, the concentration of alcohol in the mist is gradually reduced. Accordingly, the apparatus has a disadvantage that the concentration of alcohol in a solution, which is obtained by collecting mist, reduces, though the mist with a high concentration of alcohol is produced by means of ultrasonic waves.
Reduction of the concentration of alcohol in the mist can be held in check by lowering the temperature of carrier gas in the ultrasonic atomization chamber. The reason is that the total amount of alcohol and water in a vapor state, which the carrier gas can hold, varies depending on the temperature. When the temperature is low, the total amount is also low. On the other hand, if the temperature of the carrier gas in the ultrasonic atomization chamber is low, the efficiency of atomization for producing mist from a solution is remarkably reduced. In this case, it is difficult to efficiently produce high-concentrated mist from a solution. This requires high ultrasonic oscillation power for producing the mist. In order to achieve this requirement, it is necessary to increase the performance of the ultrasonic oscillator and a power source for driving the ultrasonic oscillator, thus, both equipment costs and running costs should be high. Such an apparatus is not economical.
Therefore, the present invention has been developed to solve the above disadvantages. It is an important object to provide an ultrasonic separator that is capable of efficiently producing mist from a solution in an ultrasonic atomization chamber, and of collecting a target material included in the mist produced from the solution whereby efficiently separating a high-concentrated solution.
The above and further objects and features of the invention will more fully be apparent from the following detailed description with accompanying drawings.